GP13401 GP-PRO20 ULTRA-FINE Grade Sanding Disc for Glass, Silicon Carbide Abrasive Disc / 4.5-Inch (Pack of 10) Discs diameter: 4.5 inch / Pack of 10 Discs Constructed from top grade silicon carbide, with orange velour backing for use with any Velcro backing pad GP-PRO100 Ultra-Fine Grade for removing surface scratches, haziness, scuffs from any plastic and acrylic surface. Recommended to use with electric rotary device ( drill, polishing machine ) at about 1500-2000rpm. For best results final polishing process is required. Please check detailed product description for more information's.